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Competing Interests: The authors report no conflicts of interest.

Competing Interests: The authors report no conflicts of interest.

Background Context: Long-term follow-up of patient-reported outcome measures (PROM) is essential in both modern spinal care and research. Lack of time and staff are commonly reported barriers to implementing long-term follow-up of PROM. Automated and digital follow-up systems for PROM collection are seeing widespread use, yet their validity and comparative effectiveness have never been evaluated., Purpose: The present study aimed to assess the validity of digital follow-up systems in comparison with the conventional paper-based follow-up (PB-FU)., Study Design: This is a retrospective analysis of prospectively collected double follow-up data., Patient Sample: Patients who underwent lumbar spinal fusion for spondylolisthesis or degenerative disc disease between 2013 and 2016 were included in the study., Outcome Measures: The study determined the Oswestry Disability Index (ODI) and Numeric Rating Scale (NRS) for back and leg pain severity at baseline, 6 weeks, 12 months, and 24 months., Materials and Methods: After lumbar spinal fusion surgery, a double follow-up of PROM was carried out by conventional PB-FU during clinical visits, while simultaneously completing an automatically dispatched digital follow-up questionnaire. As the primary end point, we assessed the intraindividual discrepancy in PROM between PB-FU and automated digital follow-up (AD-FU)., Results: Forty patients completed all parts of the dual follow-up trajectory and were analyzed. We detected no discrepancy in ODI or NRS for back and leg pain severity at any of the baseline, 6-week, 12-month, or 24 month follow-ups (all p>.05). This was confirmed in a sensitivity analysis., Conclusions: In an analysis of dual paper-based and digital follow-up after lumbar fusion surgery, patients report highly similar values using either method of follow-up. It appears that AD-FU without incentives produces lower response rates. To reassess the validity of these systems for data collection in spinal patient care, a prospective validation with higher statistical power is warranted., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Far lateral interbody fusion is a minimally invasive operating technique. However, the incidence of postoperative neurological complications is high, and some scholars question its safety. This study describes the neuroanatomical features and spatial orientation within the psoas major. Ten embalmed male cadavers were selected and the left psoas major was dissected. Subsequently, the area between the anterior and the posterior edges of the vertebral body was divided into three equal zones. The nerves' distribution, number, and spatial orientation of the L1/2 to L4/5 intervertebral discs were examined. A caliper was used to measure the diameter of the nerve. The safety zone of the L1/2 intervertebral disc level is located in zone I and II, the relative safe zones of the L2/3 and L4/5 intervertebral discs are located in zone II, and the safety zone of the L3/4 intervertebral disc level is located in the caudal side of zone II. The genitofemoral nerve exits the psoas major in a co-trunk or two-branch pattern, and its exit point was distributed between the L3 and L4 vertebral bodies, mainly at the L3/4 intervertebral disc level. The sympathetic ganglia in the psoas major appeared only in zone I at the L2/3 intervertebral disc level. This is a systematic anatomical study that describes the nerves of the psoas major. Spine surgeons can use this study-which consists of important clinical implications-for preoperative planning, and thus, reduce the risk of nerve injury during surgery., (© 2023 American Association of Clinical Anatomists and British Association of Clinical Anatomists.)

Aims: Historically, patients undergoing surgery for adolescent idiopathic scoliosis (AIS) have been nursed postoperatively in a critical care (CC) setting because of the challenges posed by prone positioning, extensive exposures, prolonged operating times, significant blood loss, major intraoperative fluid shifts, cardiopulmonary complications, and difficulty in postoperative pain management. The primary aim of this paper was to determine whether a scoring system, which uses Cobb angle, forced vital capacity (FVC), forced expiratory volume in one second (FEV1), and number of levels to be fused, is a valid method of predicting the need for postoperative critical care in AIS patients who are to undergo scoliosis correction with posterior spinal fusion (PSF)., Methods: We retrospectively reviewed all AIS patients who had undergone PSF between January 2018 and January 2020 in a specialist tertiary spinal referral centre. All patients were assessed preoperatively in an anaesthetic clinic. Postoperative care was defined as ward-based (WB) or critical care (CC) , based on the preoperative FEV1, FVC, major curve Cobb angle, and the planned number of instrumented levels., Results: Overall, 105 patients were enrolled. Their mean age was 15.5 years (11 to 25) with a mean weight of 55 kg (35 to 103). The mean Cobb angle was 68° (38° to 122°). Of these, 38 patients were preoperatively scored to receive postoperative CC. However, only 19% of the cohort (20/105) actually needed CC-level support. Based on these figures, and an average paediatric intensive care unit stay of one day before stepdown to ward-based care, the potential cost-saving on the first postoperative night for this cohort was over £20,000. There was no statistically significant difference between the Total Pathway Score (TPS), the numerical representation of the four factors being assessed, and the actual level of care received (p = 0.052) or the American Society of Anesthesiologists grade (p = 0.187). Binary logistic regression analysis of the TPS variables showed that the preoperative Cobb angle was the only variable which significantly predicted the need for critical care., Conclusion: Most patients undergoing posterior fusion surgery for AIS do not need critical care. Of the readily available preoperative measures, the Cobb angle is the only predictor of the need for higher levels of care, and has a threshold value of 74.5°., Competing Interests: M. P. Grevitt reports payment or honoraria for lectures, presentations, speakers bureaus, manuscript writing or educational events from DePuy Synthes, unrelated to this study., (© 2024 The British Editorial Society of Bone & Joint Surgery.)

Purpose: In patients with neuromuscular scoliosis undergoing posterior spinal fusion, the S2 alar iliac (S2AI) screw trajectory is a safe and effective method of lumbopelvic fixation but can lead to implant prominence. Here we use 3D CT modeling to demonstrate the anatomic feasibility of the S1 alar iliac screw (S1AI) compared to the S2AI trajectory in patients with neuromuscular scoliosis., Methods: This retrospective study used CT scans of 14 patients with spinal deformity to create 3D spinal reconstructions and model the insertional anatomy, max length, screw diameter, and potential for implant prominence between 28 S2AI and 28 S1AI screw trajectories., Results: Patients had a mean age of 14.42 (range 8-21), coronal cobb angle of 85° (range 54-141), and pelvic obliquity of 28° (range 4-51). The maximum length and diameter of both screw trajectories were similar. S1AI screws were, on average, 6.3 ± 5 mm less prominent than S2AI screws relative to the iliac crests. S2AI screws were feasible in all patients, while in two patients, posterior elements of the lumbar spine would interfere with S1AI screw insertion., Conclusion: In this cohort of patients with neuromuscular scoliosis, we demonstrate that the S1AI trajectory offers comparable screw length and diameter to an S2AI screw with less implant prominence. An S1AI screw, however, may not be feasible in some patients due to interference from the posterior elements of the lumbar spine., (© 2024. This is a U.S. Government work and not under copyright protection in the US; foreign copyright protection may apply.)

Study Design: Retrospective cohort study., Objective: To assess the impact of preoperative symptom duration (PSD) on patient-reported outcome measures (PROMs) after minimally invasive (MIS) transforaminal lumbar interbody fusion (TLIF) for degenerative spondylolisthesis (DSpond)., Background: A prolonged duration of preoperative symptoms may implicate inferior long-term outcomes postsurgery. Prior studies of lumbar fusion recipients are limited by the inclusion of heterogeneous populations., Methods: A single-surgeon registry was retrospectively queried for privately insured patients who had undergone primary, elective, single-level MIS-TLIF for DSpond with a recorded symptom start date. Cohorts were formed by PSD: shorter duration (PSD <1 y) or greater duration (GD; PSD ≥1 y). PROMs evaluated included Patient-reported Outcomes Measurement Information System-Physical Function, Oswestry Disability Index, Visual Analog Scale-Back, Visual Analog Scale-Leg, and 9-item Patient Health Questionnaire. The magnitude of PROM (∆PROM) improvement from preoperative baseline to 6 weeks and final follow-up (∆PROM-FF) were compared between cohorts. Intercohort achievement rates of a minimum clinically important difference in each PROM were compared., Results: A total of 133 patients included 85 patients with GD cohort. There were no significant differences in pre hoc demographics and perioperative characteristics between cohorts, as well as preoperative, 6-week, or final follow-up PROMs between cohorts. Both cohorts demonstrated significant improvement in all PROMs at 6 weeks and final follow-up ( P ≤ 0.049, all). There were no significant intercohort differences demonstrated in minimum clinically important difference achievement rates, ∆PROM-6W, or ∆PROM-FF in any PROM., Conclusions: Regardless of the symptom duration before MIS-TLIF for DSpond, patients demonstrate significant improvement in physical function, pain, disability, and mental health. Patients with a GD of preoperative symptoms did not report inferior scores in any PROM domain. Patients with a GD of preoperative symptoms did not suffer inferior rates of clinically meaningful improvement after surgical intervention. These findings should be considered when counseling patients before surgical intervention for DSpond., Competing Interests: The authors declare no conflict of interest., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Purpose: Operative treatment of adult spinal deformity (ASD) has been shown to improve patient health-related quality of life (HRQOL). Selection of the uppermost instrumented vertebra (UIV) in either the upper thoracic (UT) or lower thoracic (LT) spine is a pivotal decision with effects on operative and postoperative outcomes. This review overviews the multifaceted decision-making process for UIV selection in ASD correction., Methods: PubMed was queried for articles using the keywords "uppermost instrumented vertebra", "upper thoracic", "lower thoracic", and "adult spinal deformity"., Results: Optimization of UIV selection may lead to superior deformity correction, better patient-reported outcomes, and lower risk of proximal junctional kyphosis (PJK) and failure (PJF). Patient alignment characteristics, including preoperative thoracic kyphosis, coronal deformity, and the magnitude of sagittal correction influence surgical decision-making when selecting a UIV, while comorbidities such as poor body mass index, osteoporosis, and neuromuscular pathology should also be taken in to account. Additionally, surgeon experience and resources available to the hospital may also play a role in this decision. Currently, it is incompletely understood whether postoperative HRQOLs, functional and radiographic outcomes, and complications after surgery differ between selection of the UIV in either the UT or LT spine., Conclusion: The correct selection of the UIV in surgical planning is a challenging task, which requires attention to preoperative alignment, patient comorbidities, clinical characteristics, available resources, and surgeon-specific factors such as experience., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Introduction: The atypical anatomy of the C2 vertebra has led to terminological discrepancies within reports and studies in the literature regarding the location of its pedicle, pars interarticularis, and isthmus. These discrepancies not only limit the power of morphometric analyses, but they also confuse technical reports regarding operations involving C2, and thus confuse our ability to properly communicate this anatomy. Herein, we examine the variations in nomenclature regarding the pedicle, pars interarticularis, and isthmus of C2, and via an anatomical study, propose new terminology., Methods: The articular surface and underlying superior and inferior articular processes and adjacent transverse processes were removed from 15 C2 vertebrae (30 sides). Specifically, the areas regarded as the pedicle, pars interarticularis, and isthmus were evaluated. Morphometrics were performed., Results: Our results indicate that, anatomically, C2 has no "isthmus" and that a pars interarticularis for C2, when present, is very short. Deconstruction of the attached parts allowed for visualization of a bony arch extending from the anterior most aspect of the lamina to the body of C2. The arch is composed almost entirely of trabecular bone and without its attached parts, e.g., transverse process, really has no cortical bone laterally., Conclusions: We propose a more accurate terminology, the pedicle, for pars/pedicle screw placement of C2. Such a term more accurately describes this unique structure of the C2 vertebra and would alleviate terminological confusion in the future literature on this topic., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature.)

Objective: Pulmonary function can be impaired in patients with adolescent idiopathic scoliosis (AIS). Maximal voluntary ventilation (MVV) has been shown to be more strongly correlated with major coronal curve, and a more easily obtained measurement of pulmonary function, than forced vital capacity (FVC). We evaluated changes in pulmonary function using these 2 measures in patients with AIS in relation to changes in major coronal curves over time., Methods: Forty-seven patients with AIS with thoracic curves ≥10 degrees performed pulmonary function tests using the Carefusion MicroLoop Spirometer at enrollment and 1 year later. Major coronal curve worsening >5 degrees was considered curve progression., Results: At enrollment, 47 patients had a mean major coronal curve of 38 degrees (range: 10 to 76 degrees). One year later, 17 patients had undergone posterior spinal fusion, 9 had curve progression >5 degrees, and 21 had no progression. MVV and major coronal curve were negatively correlated (r = -0.36, P = 0.01) at enrollment. After fusion, the major coronal curve improved by a mean of 41 degrees, and MVV improved by 23% (P < 0.01), but FVC did not improve significantly (6%, P = 0.29). In stable curves, MVV improved 12% (P = 0.01) and FVC improved 9% (P = 0.007). In patients without surgery whose curves progressed an average of 11 degrees, there was no significant change in MVV or FVC (P > 0.44)., Conclusion: This is the first study using office-based spirometry in an orthopaedic clinic showing improved pulmonary function with posterior spinal fusion and growth in patients with AIS. It is notable that MVV improved after spinal fusion, but FVC did not, as MVV appears to be a more sensitive measurement for the assessment of pulmonary function in these patients., Level of Evidence: Level II., Competing Interests: The authors declare no conflicts of interest., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Background: Low socioeconomic status (SES) has been previously associated with delays in orthopaedic care. However, it is unclear how SES impacts patients with adolescent idiopathic scoliosis (AIS), particularly regarding preoperative major coronal curve angle or surgical outcomes. Utilizing the Child Opportunity Index (COI)-an address-driven measure of pediatric education, health/environment, and SES-we investigated whether COI is associated with differences in preoperative scoliosis magnitude, age at surgery, and AIS surgical outcomes., Methods: Consecutive patients with AIS surgically treated at a single center from 2011 to 2017 were reviewed. COI was calculated by inserting a patient's home address into the nationally available COI database to derive a COI value. COI is scored from 0.0 to 100.0 (0.0 is lowest, 100.0 is highest). Specifically, COI is categorized as very low (<20.0), low (20 to 39.9), moderate (40 to 59.9), high (60 to 79.9), and very high (≥80). Those without addresses were excluded. Patients without proper radiographs to assess curve correction were also excluded. A COI threshold of 60.0 was used to separate patients into a low (<60.0) or high COI ( ) group based on published COI guidelines. Outcomes, including preoperative curve magnitude, age at surgery, percentage curve correction, operative time (OT), intraoperative estimated blood loss per level fused, length of stay, and complications, were compared across groups. Pearson correlation analysis was used to assess correlations between COI and preoperative curve magnitude, as well as age., Results: Four hundred four patients were included in the study, and 263 had 2-year follow-up data. Patients were an average age of 14.9 years old (range: 11.2 to 19.8), had a median COI of 76 (range: 4 to 100), and had a mean preoperative major curve angle of 59 degrees (range: 36 to 93). COI was significantly higher for white patients compared with non-white (80.0 vs 40.0, P < 0.001), and higher for non-Hispanic individuals (79.0 vs 15.0, P < 0.001). Patients with Low COI were associated with a lower OT per level fused ( P = 0.003) and decreased postoperative complication risk ( P = 0.02). COI was not associated with preoperative major coronal curve angle, age at surgery, or any other surgical outcomes., Conclusion: COI was significantly lower for non-white patients and those of Hispanic ethnicity. Patients from low COI backgrounds achieved similar surgical results as those from high COI addresses and had a decreased OT per level fused and complication incidence, though the clinical significance of these differences is unknown. Future prospective studies are needed to determine whether these findings are reproducible across other states and health systems., Level of Evidence: Level III-prognostic study., Competing Interests: The authors declare no conflicts of interest., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Background: Tranexamic acid (TXA) has been utilized in spinal surgery to effectively reduce intraoperative blood loss (IBL) and allogeneic blood transfusion rates. However, the traditional TXA regimen might last the entire duration of hyperfibrinolysis caused by surgical trauma, resulting in its limited ability to reduce postoperative blood loss (PBL). Therefore, the aim of this study was to investigate the effectiveness of perioperative sequential administration of multiple doses of TXA in reducing PBL in patients who underwent posterior lumbar interbody fusion (PLIF)., Methods: From October 2022 to June 2023, 231 patients who were diagnosed with lumbar degenerative disease and scheduled to undergo PLIF were prospectively enrolled in the present study. The patients were randomly divided into three groups. Moreover, all patients received an intravenous injection of TXA at a dose of 15 mg/kg 15 min before the surgical skin incision. Patients in Group A received a placebo of normal saline after surgery, while patients in Group B received three additional intravenous injections of TXA at a dose of 15 mg/kg every 24 h. Patients in Group C received three additional intravenous injections of TXA at a dose of 15 mg/kg every 5 h. The primary outcome measure was PBL. In addition, this study assessed total blood loss (TBL), IBL, routine blood parameters, liver and kidney function, coagulation parameters, fibrinolysis indexes, inflammatory indicators, drainage tube removal time (DRT), length of hospital stay (LOS), blood transfusion rate, and incidence of complications for all subjects., Results: The PBL, TBL, DRT, and LOS of Group B and Group C were significantly lower than those of Group A ( P <0.05). The level of D-dimer (D-D) in Group C was significantly lower than that in Group A on the first day after the operation ( P =0.002), and that in Group B was significantly lower than that in Group A on the third day after the operation ( P =0.003). The interleukin-6 levels between the three groups from 1 to 5 days after the operation were in the order of Group A > Group B > Group C. No serious complications were observed in any patient. The results of multiple stepwise linear regression analysis revealed that PBL was positively correlated with incision length, IBL, smoking history, history of hypertension, preoperative fibrinogen degradation product level, and blood transfusion. It was negatively correlated with preoperative levels of fibrinogen, red blood cells, blood urea nitrogen, and age. Compared to female patients, male patients had an increased risk of PBL. Finally, the incidence of PBL was predicted., Conclusions: Sequential application of multiple doses of TXA during the perioperative period could safely and effectively reduce PBL and TBL, shorten DRT and LOS, reduce postoperative D-D generation, and reduce the postoperative inflammatory response. In addition, this study provided a novel prediction model for PBL in patients undergoing PLIF., (Copyright © 2024 The Author(s). Published by Wolters Kluwer Health, Inc.)

Purpose : Finite element analysis is frequently used for lumbar spine biomechanical analysis. The primary scope of this work is to illustrate, using finite element analysis, how the biomechanical behavior of the transforaminal lumbar interbody fusion (TLIF), along with a novel combination of the interspinous process device (IPD) and pedicle screws, improves lumbar spine stability. Methods : In this study, unilateral pedicle screw fixation (UPSF) and bilateral pedicle screw fixation (BPSF) were used. Four FE models were developed using ANSYS software, as follows: (1) Intact model; (2) TLIF with "U"-shaped Coflex-F IPD (UCF); (3) TLIF with Coflex-F and UPSF (UCF + UPSF); (4) TLIF with Coflex-F and BPSF (UCF + BPSF). The intact model was subjected to four pure moments (10 Nm), and the results were validated with previous literature data. The intact model results correlated well with the literature data, and the model was validated. Three surgical models were subjected to 7.5 Nm four pure moments, flexion (FL), extension (ET), lateral bending (LB), and axial rotation (AR) and a 280N follower load. Results : The surgical model results were compared with the intact model. The comprehensive analysis results show the UCF + BPSF surgical model gave a good advantage on range of motion, cage stress, Coflex-F stress and endplate stress compared among the two models. Conclusion : This study proposes that the UCF + BPSF system helps to reduce the stress on the implant and adjacent endplates and gives very good stability to the lumbar spine under the various static loading conditions., (© 2023 S. Meganathan et al., published by Sciendo.)

Study Design: A single-centre retrospective study., Background and Purpose: This study aims to investigate the rate of L5 radiculopathy, to identify imaging features associated with the complication and to evaluate the clinical outcomes in adult spine deformity patients undergoing L5-S1 ALIF with hyperlordotic cages., Methods: Design: retrospective cohort study. A single-centre prospective database was queried to analyse patients undergoing hyperlordotic (HL) ALIF with posterior fusion to correct spinal deformity. Clinical status was evaluated by back and leg pain numeric rate scale and Oswestry Disability Index pre-operatively and at 3-, 6- and 12-month follow-up. Spinopelvic parameters, such as pelvic incidence, pelvic tilt, lumbar lordosis and L5-S1 lordosis, posterior disc height (PDH) and anterior disc height, were assessed pre-operatively and post-operatively on standardized full-spine standing EOS images. The sagittal foraminal area was measured pre- and post-operatively on a CT scan., Results: Thirty-nine patients with a mean age of 63.2 ± 8.6 years underwent HL-ALIF from January 2016 to December 2019. Seven of them developed post-operative root pain (5) or weakness (2) (Group A), while thirty-two did not (Group B). Root impairment was associated with greater segmental correction magnitude, 26° ± 11.1 in Group A versus 15.1° ± 9.9 in Group B (p < 0.05), and to smaller post-operative PDH, 5.9 mm ± 2.7 in Group A versus 8.3 mm ± 2.6 (p < 0.05)., Conclusions: Post-operative root problems were observed in 17.9% of patients undergoing HL-ALIF for adult spine deformity. L5 radiculopathy was associated with larger sagittal angular corrections and smaller post-operative posterior disc height. One patient (2.6%) needed L5 root decompression. At 12 months of follow-up, results were equivalent between groups., Level of Evidence I: Diagnostic: individual cross-sectional studies with the consistently applied reference standard and blinding., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Purpose: This study aims to assess the correlation between the patient-reported mental health and the self-reported outcome measures (PROMs) physical function, pain, and disability at different time points following disc replacement (CDR)., Methods: A single-surgeon registry was searched for patients who had undergone CDR, excluding those with indication for infection, cancer, or trauma. One hundred fifty-one patients were included. PROMs were collected preoperatively as well as 6 weeks, 3 months, 6 months, and 1 year postoperatively. Mental health measures evaluated included 12-Item Short Form (SF-12), Mental Component Score (MCS), and Patient Health Questionnaire-9 (PHQ-9) which were individually assessed via Pearson's correlation tests in relation to Patient-Reported Outcome Measurement Information System Physical Function (PROMIS-PF), SF-12 Physical Component Score (PCS), visual analog scale (VAS) neck and arm pain, and Neck Disability Index (NDI)., Results: SF-12 MCS positively correlated with PROMIS-PF (range: r = 0.369-0.614) and SF-12 PCS (range: r = 0.208-0.585) with significance found at two or more time points for each (p ≤ 0.009, all). SF-12 MCS negatively correlated with VAS neck (range: r = - 0.259 to - 0.464), VAS arm (range: r = - 0.281 to - 0.567), and NDI (range: r = - 0.474 to - 831) with significance found at three or more time points (p ≤ 0.028, all). PHQ-9 significantly negatively correlated with PROMIS-PF (range: r = - 0.457 to - 0.732) and SF-12 PCS (range: r = - 0.332 to - 0.629) at all time points (p ≤ 0.013, all). PHQ-9 positively correlated with VAS neck (range: r = 0.351-0.711), VAS arm (range: r = 0.239-0.572), and NDI (range: r = 0.602-0.837) at four or more periods (p ≤ 0.032, all)., Conclusion: Patients undergoing CDR who reported lower mental health scores via either SF-12 MCS or PHQ-9 were associated with increased perception of pain and disability. Disability level correlated with mental health at all time periods. Patients with optimized mental health may report higher outcome scores following CDR., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature.)

Personalized medicine has made a tremendous impact on patient care. Although initially, it revolutionized pharmaceutical development and targeted therapies in oncology, it has also made an important impact in orthopaedic surgery. The field of spine surgery highlights the effect of personalized medicine because the improved understanding of spinal pathologies and technological innovations has made personalized medicine a key component of patient care. There is evidence for several of these advancements to support their usage in improving patient care. Proper understanding of normative spinal alignment and surgical planning software has enabled surgeons to predict postoperative alignment accurately. Furthermore, 3D printing technologies have demonstrated the ability to improve pedicle screw placement accuracy compared with free-hand techniques. Patient-specific, precontoured rods have shown improved biomechanical properties, which reduces the risk of postoperative rod fractures. Moreover, approaches such as multidisciplinary evaluations tailored to specific patient needs have demonstrated the ability to decrease complications. Personalized medicine has shown the ability to improve care in all phases of surgical management, and several of these approaches are now readily available to orthopaedic surgeons., (Copyright © 2023 by the American Academy of Orthopaedic Surgeons.)

Purpose: The iliac fixation (IF) through the S2 ala permits the minimization of implant prominence and tissue dissection. An alternative to this technique is the anatomic iliac screw fixation (AI), which considers the perpendicular axis to the narrowest width of the ileum and the width of the screw. The morphological accuracy of the iliac screw insertion of two low profile iliac fixation (IF) techniques is investigated in this study., Methods: Twenty-nine patients operated on via low profile IF technique were divided into two groups, those treated using 28 screws with the starting point at S2, and those treated with 30 AI entry point. Radiological parameters (Tsv-angle, Sag-Angle, Max-length, sacral-distance, iliac-width, S2-midline, skin-distance, iliac-wing, and PSIS distance) and clinical outcomes (early and clinic complications) were evaluated by two blinded expert radiologists, and the results were compared in both groups with the real trajectory of the screws placed., Results: Differences between ideal and real trajectories were observed in 6 of the 9 evaluated parameters in the S2AI group. In the AI group, these trajectories were similar, except for TSV-Angle, Max-length, Iliac-width, and distance to iliac-wing parameters. Moreover, compared with S2AI, AI provided better adaptation to the pelvic morphology in all parameters, except for sagittal plane angulation, skin distance, and iliac width., Conclusions: AI ensures the advantages of low profile pelvic fixation like S2AI, with a starting point in line with S1 pedicle anchors and low implant prominence, and moreover adapts better to the morphological features of the pelvis of each individual., (© 2023. The Author(s).)

Introduction: Posterior lumbar fusion surgery has become more common amid an aging population, with degenerative disease as its most common indication. Historically, postoperative pain control for spine surgery has relied on opioids. However, opioid use is associated with adverse effects such as dependence, respiratory depression, and altered cognition. Our study aimed to determine whether an opioid-sparing multimodal analgesia regimen (ketorolac, orphenadrine, and gabapentin) could be a viable alternative to diminish opioid use compared with a standard opioid-based regimen in Hispanic patients undergoing posterior lumbar spinal fusion., Methods: This was a randomized controlled trial of Hispanic patients scheduled to undergo elective posterior spinal fusion. Inclusion criteria included age 30 to 85 years, Hispanic ethnicity, lumbar stenosis between L1 and S1, elective posterior spinal fusion with instrumentation, American Society of Anesthesiologists Score <2, and consent to participate in the study. Patients were randomized into two groups, an experimental multimodal analgesia and control (opioid-based) treatment groups, and outcomes such as morphine milligram equivalents used, visual analog scale score, and length of hospital stay were compared between the groups., Results: The MMA experimental group used significantly lower amounts of opioid (measured with morphine milligram equivalent) than the opioid-based group during the 12-hour and 24-hour postoperative periods ( P -value = 0.023 and P -value = 0.033, respectively). No statistically significant difference was observed in opioid use in the 48-hour postoperative period between both groups ( P -value = 0.066). The MMA group had significantly lower VAS scores reported at the 12-hour, 24-hour, and 48-hour postoperative periods compared with the opioid-based group ( P -values = 0.016, 0.020, and 0.020, respectively). No difference was observed in the length of hospital stay between groups ( P -value = 0.169)., Discussion: Implementing an MMA protocol in Hispanic patients undergoing posterior lumbar fusion resulted in decreased overall opioid use and decreased pain intensity compared with the opioid-based group. MMA is an effective alternative for pain control in patients who want to avoid opioid use., Clinical Trial Registration: Identifier: NCT05413902., (Copyright © 2023 by the American Academy of Orthopaedic Surgeons.)

Purpose: To describe the surgical technique and methodology to successfully plan and execute an endoscopic foraminotomy in patients with isthmic or degenerative spondylolisthesis, according to each patient's unique characteristics., Methods: Thirty patients with degenerative or isthmic spondylolisthesis (SL) with radicular symptoms were included from March 2019 to September 2022. Treating physician registered patients' baseline and imaging characteristics, as well as preoperative back pain VAS, leg pain VAS and ODI. Subsequently, authors treated the included patients with an endoscopic foraminotomy according to a "patient-specific" tailored approach., Results: Nineteen patients (63.33%) had isthmic SL and 11 patients (36.67%) had degenerative SL. 75.86% of the cases had a Meyerding Grade 1 listhesis. One of the transforaminal foraminotomies with lateral recess decompression in degenerative SL had to be aborted because of intense osseous bleeding. Of the remaining 29 patients, one patient experienced recurrence of the sciatica pain that required subsequent reintervention and fusion. No other intraoperative or post-operative complications were observed. None of the patients developed post-operative dysesthesia. In 86.67% of the patients, the foraminotomy was implemented using a transforaminal approach. In the remaining 13.33% of the cases, an interlaminar contralateral approach was used. Lateral recess decompression was performed in half of the cases. Mean follow-up time was 12.69 months, reaching a maximum of 40 months in some patients. Outcome variables such as VAS for leg and back pain, as well as ODI, showed statistically significant reduction since the 3-month follow-up visit., Conclusion: In the presented case series, endoscopic foraminotomy achieved satisfactory outcomes without sacrificing segmental stability. The proposed patient-specific "tailored" approach allowed to successfully design and execute the surgical strategy to perform an endoscopic foraminotomy through transforaminal or interlaminar contralateral approaches., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Study Design: This was a retrospective comparative study., Objective: To compare the likelihood of approach-related complications for patients undergoing single-level lateral lumbar interbody fusion (LLIF) at L4-L5 to those undergoing the procedure at upper lumbar levels., Summary of Background Data: LLIF has been associated with a number of advantages when compared with traditional interbody fusion techniques. However, potential risks with the approach include vascular or visceral injury, thigh dysesthesias, and lumbar plexus injury. There are concerns of a higher risk of these complications at the L4-L5 level compared with upper lumbar levels., Materials and Methods: A retrospective cohort review was completed for consecutive patients undergoing single-level LLIF between 2004 and 2019 by a single surgeon. Indication for surgery was symptomatic degenerative lumbar stenosis and/or spondylolisthesis. Patients were divided into 2 cohorts: LLIF at L4-L5 versus a single level between L1 and L4. Baseline characteristics, intraoperative complications, postoperative approach-related neurological symptoms, and patient-reported outcomes were compared and analyzed between the cohorts., Results: A total of 122 were included in analysis, of which 58 underwent LLIF at L4-L5 and 64 underwent LLIF between L1 and L4. There were no visceral or vascular injuries or lumbar plexus injuries in either cohort. There was no significant difference in the rate of postoperative hip pain, anterior thigh dysesthesias, and/or hip flexor weakness between the cohorts (53.5% L4-L5 vs. 37.5% L1-L4; P =0.102). All patients reported complete resolution of these symptoms by 6-month postoperative follow-up., Discussion: LLIF surgery at the L4-L5 level is associated with a similar infrequent likelihood of approach-related complications and postoperative hip pain, thigh dysesthesias, and hip flexor weakness when compared with upper lumbar level LLIF. Careful patient selection, meticulous use of real-time neuromonitoring, and an understanding of the anatomic location of the lumbar plexus to the working corridor are critical to success., Competing Interests: F.M.P. has Royalties and Stock Ownership with Nuvasive. The remaining authors declare no conflict of interest., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

Background: Combination of apical control convex pedicle screws (ACPS) with traditional dual growing rods (TDGRs) had better apex control ability for early-onset scoliosis (EOS); however, there is a paucity of studies on the ACPS technique., Objective: To compare 3-dimensional deformity correction parameters and complications between the apical control technique (DGR + ACPS) and TDGR in the treatment of EOS., Methods: A retrospective case-match analysis consisting of 12 cases of EOS treated with the DGR + ACPS technique (group A) from 2010 to 2020, and matched with TDGR case (group B) at a ratio of 1:1 by age, sex, curve type, major curve degree, and apical vertebral translation (AVT). Clinical assessment and radiological parameters were measured and compared., Results: Demographic characteristics, preoperative main curve, and AVT were comparable between groups. The correction ability of the main curve, AVT, and apex vertebral rotation were better in group A at index surgery ( P < .05). The increase in T1-S1 and T1-T12 height was large in group A at index surgery ( P = .011, P = .074). The annual increase in spinal height was slower in group A, but without significant difference. The surgical time and estimated blood loss were comparable. Six complications occurred in group A, and 10 occurred in group B., Conclusion: In this preliminary study, ACPS seems to provide better correction of apex deformity, while attaining the comparable spinal height at 2-year follow-up. Larger cases and longer follow-up are needed to achieve reproducible and optimal results., (Copyright © 2023 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the Congress of Neurological Surgeons.)

Purpose: Obesity is associated with increased surgical complexity and postoperative complications in spine surgery. Minimally invasive procedures have been shown to lessen some of the increased risk in obese patients. This study investigated whether utilization of a working channel endoscope can further mitigate obesity-associated challenges in spinal surgery., Methods: A retrospective review of a single-surgeon database was conducted for all adult patients undergoing full-endoscopic unilateral laminotomies for bilateral decompression between November 2015 and March 2021. Data collected included body mass index, in operating room preparation time, procedure time, length of hospital stay, use of analgesics, complications, and quality of life measured by Oswestry Disability Index., Results: Our cohort included 174 patients. Of these, 74 (42.5%) were obese. The average age was 63.6 years. In-operating room preparation time was 70.0 ± 1.7 min for obese patients and 64.4 ± 1.5 min for non-obese patients (p = 0.02). There was no difference in operative time, durotomy rates or other perioperative complications between obese and non-obese patients. Hospital length of stay trended toward longer in the obese group, but did not reach significance. A greater percentage of obese patients were still using both narcotic and non-narcotic pain medications 2 weeks after surgery. There was no significant difference in functional outcomes between groups., Conclusion: Full-endoscopic unilateral laminotomies for bilateral decompression are safe and effective in both non-obese and obese patients. The use of an endoscope can partially mitigate obesity-related morbidity in lumbar decompression. However, obesity is significantly related to increased postoperative analgesic use., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Background: There is limited literature on the outcomes in patients with osteogenesis imperfecta (OI) undergoing growth-friendly instrumentation (GFI). The purpose of this study was to report the outcomes of GFI in patients with early-onset scoliosis (EOS) and OI. We hypothesized that similar trunk elongation could be obtained in OI patients, but with higher complication rates., Methods: A multicenter database was studied for patients with EOS and OI etiology who had GFI from 2005 to 2020, with a minimum 2-year follow-up. Demographic, radiographic, clinical, and patient-reported outcomes data were collected and compared with an idiopathic EOS cohort matched 2:1 for age, follow-up duration, and curve magnitude., Results: Fifteen OI patients underwent GFI at a mean age of 7.3±3.0 years, with an average follow-up of 7.3±3.9 years. OI patients had a mean preoperative coronal curve of 78.1±14.5 and achieved 35% correction after index surgery. There were no differences in major coronal curves and coronal percent correction between the OI and idiopathic groups at all time points. T1-S1 length (cm) was lower for the OI group at baseline (23.3±4.6 vs. 27.7±7.0; P =0.028) but both groups had similar growth (mm) per month (1.0±0.6 vs. 1.2±1.1; P =0.491). OI patients had a significantly increased risk of proximal anchor failure, which occurred in 8 OI patients (53%) versus 6 idiopathic patients (20%) ( P =0.039). OI patients who underwent preoperative halo-traction (N=4) had greater T1-S1 length gain (11.8±3.2 vs. 7.3±2.8; P =0.022) and greater percent major coronal curve correction (45±11 vs. 23±17; P =0.042) at final follow-up versus patients with no halo-traction (N=11). Staged foundation fusion was performed in 2 cases., Conclusion: Compared with matched idiopathic EOS patients, OI patients undergoing GFI achieved similar radiographic outcomes but sustained greater rates of anchor failures, likely due to weakened bone. Preoperative halo-traction was a useful adjunct and may improve final correction. Staged foundation fusion is an idea to consider for difficult cases., Level of Evidence: Therapeutic-III., Competing Interests: The authors have the following conflicts of interest to declare. B.A.: Stryker, Nuvasive, DePuy, A Johnson & Johnson Company: IP royalties. NociMed: Stock or stock Options. Pediatric Spine Foundation, San Diego Spine Foundation: Board or committee member. Spine, Spine Deformity (SRS Journal): Editorial or governing board. Springer: Publishing royalties, financial or material support. P.D.S.: DePuy, A Johnson & Johnson Company: IP royalties; Paid consultant; Research support. Globus Medical: IP royalties. Journal of Bone and Joint Surgery: Editorial or governing board. Journal of Bone and Joint Surgery—American: Publishing royalties, financial or material support. Orthpediatrics: Other financial or material support. Scoliosis Research Society: Board or committee member. The remaining authors declare no conflicts of interest., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

Background: Limited spine literature has studied the strength of association of mental health with other outcomes at time of survey collection. We aim to evaluate the degree to which mental health correlates with outcomes in patients undergoing minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) at several postoperative periods., Methods: Patients having undergone elective MIS-TLIF were searched within a retrospective single-surgeon database. Five hundred eighty-five patients were included. Patient-reported outcomes (PROs) including Patient-Reported Outcome Measurement Information System Physical Function (PROMIS PF), 12-item Short Form Physical Component Score (SF-12 PCS) and Mental Component Score (SF-12 MCS), Patient Health Questionnaire-9 (PHQ-9), Visual Analog Scale (VAS) back and leg pain, and Oswestry Disability Index (ODI) scores were collected preoperatively and at 6-week, 12-week, 6-month, 1-year, and 2-year periods. Pearson's correlation tests were used to evaluate the association between both SF-12 MCS and PHQ-9 scores to other PROs at each period., Results: SF-12 MCS correlated with PROMIS PF (|r|= 0.308-0.531), SF-12 PCS (|r|= 0.207-0.328), VAS back (|r|= 0.279-0.474), VAS leg (|r|= 0.178-0.395), and ODI (|r|= 0.450-0.538) at all time points (P ≤ 0.021, all) except for preoperative SF-12 PCS and 1-year VAS leg. PHQ-9 correlated with PROMIS PF (|r|= 0.366-0.701), SF-12 PCS (|r|= 0.305-0.568), VAS back (|r|= 0.362-0.714), VAS leg (|r|= 0.319-0.694), and ODI (|r|= 0.613-0.784) at all periods (P < 0.001, all)., Conclusion: Poor mental health scores were correlated with lower physical function, elevated pain scores, and higher disability. PHQ-9 scores demonstrated stronger correlation in all relationships compared to SF-12 MCS. Optimization of patient mental health may lead to improved patient perception regarding function, pain, and disability following MIS-TLIF., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature.)

Introduction: Bias undermines evidence-based decision making. To counter this, surgeons must be aware of biases that may influence studies' reported outcomes. Lumbar spinal stenosis often requires operative intervention, with multiple available surgical strategies. Our aim was to assess the role that country of origin plays in published surgical outcomes for lumbar spinal stenosis., Methods: We performed a search strategy of MEDLINE and EMBASE for all English language primary research papers evaluating operative interventions for lumbar spinal stenosis during the years 2010-2019 inclusive. Small case series and meta-analyses were excluded. Papers were assessed for outcome positivity and country of origin. Data analysis was conducted using GraphPad Prism statistical software., Results: A total of 487 papers met the inclusion criteria. Of these, 419 (86%) reported positive outcomes. Asian studies were the most likely to report positive outcomes, at 93% (220 of 236), followed by US studies at 89% (98 of 110). European studies had the lowest positive publication rate at 69% (84 of 121). Region of origin was an independent predictor of positive study outcome on multivariable analysis when controlling for different study designs and healthcare systems., Conclusion: There is an association between country of origin and positive reported outcome in studies evaluating interventions for lumbar spinal stenosis. Clinicians should consider this when making management decisions based on published evidence., Level of Evidence I: Diagnostic: individual cross-sectional studies with the consistently applied reference standard and blinding.

Purpose: We sought to characterize trends in demographics, comorbidities, and postoperative complications among patients undergoing primary and revision cervical disc replacement (pCDR/rCDR) procedures., Methods: In this retrospective database study, the Premier Healthcare database was queried from 2006 to 2019. Annual proportions or medians were calculated for patient and hospital characteristics, comorbidities, and postoperative complications associated with CDR surgery. Trends were assessed using linear regression analyses with year of service as the sole predictor., Results: A total of 16,178 pCDR and 758 rCDR cases were identified, with a median (IQR) age of 46 (39; 53) and 51 (43; 60) years among patients, respectively. The annual number of both procedures increased between 2006 and 2019, from 135 to 2220 for pCDR (p < 0.001), and from 17 to 49 for rCDR procedures (p < 0.001), with radiculopathy being the main indication for surgery in both groups. Mechanical failure was identified as a major indication for rCDR procedures with an increase over time (p = 0.002). Baseline patient comorbidity burden (p = 0.045) and complication rates (p < 0.001) showed an increase. For both procedures, an increase in outpatient surgeries and procedures performed in rural hospitals was seen (pCDR: p = 0.045; p = 0.006; rCDR: p = 0.028; p = 0.034)., Conclusion: PCDR and rCDR procedures significantly increased from 2006 to 2019. At the same time, comorbidity burden and complication rates increased, while procedures were more often performed in an outpatient and rural setting. The identification of these trends can help guide future practice and lead to further areas of research., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Purpose: The uppermost segment of the cervical vertebra or atlas (C1) is a critically important anatomical structure, housing the medulla oblongata and containing the grooves for the C1 spinal nerve and the vertebral vessels. Variations of the C1 vertebra can affect upper spine stability, and morphometric parameters have been reported to differ by population. However, there are few data regarding these parameters in Thais. The use of this bone to predict sex and age has never been reported., Methods: This study aimed to examine C1 morphometry and determine its ability to predict sex. Twelve diameter parameters were taken from the C1 vertebrae of identified skeletons (n = 104, males [n, 54], females [n, 50]). Correlation analysis was also performed for sex and age, which were predicted using machine learning algorithms., Results: The results showed that 8 of the 12 measured parameters were significantly longer in the male atlas (p < 0.05), while the remaining 4 (distance between both medial-most edges of the transverse foramen, transverse dimension of the superior articular surface, frontal plane passing through the canal's midpoint, and anteroposterior dimension of the inferior articular surface) did not differ significantly by sex. There was no statistically significant difference in these parameters on the lateral side. The decision stump classifier was trained on C1 parameters, and the resulting model could predict sex with 82.6% accuracy (root mean square error = 0.38)., Conclusion: Assertation of the morphometric parameters of the atlas is important for preoperative assessment, especially for the treatment of atlas dislocation. Our findings also highlighted the potential use of atlas measurements for sex prediction., (© 2023. The Author(s), under exclusive licence to Springer-Verlag France SAS, part of Springer Nature.)

Background: The study sought to evaluate the utility of a single supine radiograph in determining curve flexibility in early-onset scoliosis (EOS) patients., Methods: EOS patients with upright (standing/seated), supine, and side-bending radiographs who underwent spinal deformity surgery were identified. Coronal parameters included: proximal thoracic (PT) curve, main thoracic (MT) curve, and thoracolumbar/lumbar (TL/L) curve. Each radiograph was measured twice by 2 different raters. Correlation coefficients were utilized to investigate associations between the different radiographs. Interrater Correlation Coefficient (ICC) assessed intrarater and interrater reliability., Results: Thirty-seven EOS patients were identified (age at diagnosis: 7.0±2.9 y, preoperative age: 13.0±2.9 y; 73% female; etiologies: 54% idiopathic, 30% syndromic, and 16% neuromuscular). Supine PT and MT curve measurements were highly associated with corresponding side-bending measurements (PT: r=0.75, P<0.001; MT: r=0.80, P<0.001), and TL/L curves were very highly associated (TL/L: r=0.92, P<0.001). The mean absolute differences between supine and side-bending measurements were PT: 11.3±7.8 degrees, MT: 14.8±8.3 degrees, and TL/L: 16.2±7.6 degrees, where the side-bending was on average smaller than the supine measurement. The intrarater reliabilities were excellent, with an ICC ranging from 0.93 to 0.96 for side-bending films and 0.94 to 0.97 for supine films. The interrater reliability was excellent with ICC value of 0.88 for side-bending films and 0.93 for supine films., Conclusions: A single, preoperative supine radiograph was highly predictive of side-bending radiographs in patients with EOS. Supine curves measured an average of 15 degrees larger than bending curves in the MT and TL/L region. A single supine film may eliminate the need for effort-related, dual side-bending radiographs., Level of Evidence: Level II-retrospective study., Competing Interests: B.D.R. has received grants from the Pediatric Orthopaedic Society of North America and the Orthopedic Science Research Foundation. M.G.V. has received grants from the Pediatric Orthopaedic Society of North America, Orthopedic Science Research Foundation, Pediatric Spine Foundation, and Setting Scoliosis Straight Foundation. He has received royalties from Biomet. He is a paid consultant for Stryker, Biomet, and NuVasive. M.G.V. is on the Board of Directors of the Pediatric Spine Foundation, Pediatric Spine Study Group, and C4K. He is the former President of the Pediatric Orthopaedic Society of North America and is a Board Member, Chair Emeritus of the International Pediatric Orthopaedic Symposium. The remaining authors declare no conflicts of interest., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

Background: Prior "best practice guidelines" (BPG) have identified strategies to reduce the risk of acute deep surgical site infection (SSI), but there still exists large variability in practice. Further, there is still no consensus on which patients are "high risk" for SSI and how SSI should be diagnosed or treated in pediatric spine surgery. We sought to develop an updated, consensus-based BPG informed by available literature and expert opinion on defining high-SSI risk in pediatric spine surgery and on prevention, diagnosis, and treatment of SSI in this high-risk population., Materials and Methods: After a systematic review of the literature, an expert panel of 21 pediatric spine surgeons was selected from the Harms Study Group based on extensive experience in the field of pediatric spine surgery. Using the Delphi process and iterative survey rounds, the expert panel was surveyed for current practices, presented with the systematic review, given the opportunity to voice opinions through a live discussion session and asked to vote regarding preferences privately. Two survey rounds were conducted electronically, after which a live conference was held to present and discuss results. A final electronic survey was then conducted for final voting. Agreement ≥70% was considered consensus. Items near consensus were revised if feasible to achieve consensus in subsequent surveys., Results: Consensus was reached for 17 items for defining high-SSI risk, 17 items for preventing, 6 for diagnosing, and 9 for treating SSI in this high-risk population. After final voting, all 21 experts agreed to the publication and implementation of these items in their practice., Conclusions: We present a set of updated consensus-based BPGs for defining high-risk and preventing, diagnosing, and treating SSI in high-risk pediatric spine surgery. We believe that this BPG can limit variability in practice and decrease the incidence of SSI in pediatric spine surgery., Level of Evidence: Not applicable., Competing Interests: The authors declare no conflicts of interest., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

Bioreactors have been used for bone graft engineering in pre-clinical investigations over the past 15 years. The ability of bioreactor-incubated bone marrow nuclear cells (BMNCs) to enhance bone-forming potential varies significantly, and the three-dimensional (3D) distribution of BMNCs within the scaffold is largely unknown. The aims of this study were (1) to investigate the efficacy of a carbonated hydroxyapatite (CHA) with/without BMNCs on spine fusion rate and fusion mass microarchitecture using a highly challenging two-level posterolateral spine fusion without instrumentation; and (2) to evaluate 3D distribution of BMNCs within scaffolds characterized by immunohistochemistry. Fusion rate and fusion mass were quantified by micro-CT, microarchitectural analysis, and histology. While the homogenous 3D distribution of BMNCs was not observed, BMNCs were found to migrate towards a substitute core. In the autograft group, the healing rate was 83.3%, irrespective of the presence of BMNCs. In the CHA group, also 83.3% was fused in the presence of BMNCs, and 66.7% fused without BMNCs. A significant decrease in the fusion mass porosity (p = .001) of the CHA group suggested the deposition of mineralized bone. The autograft group revealed more bone, thicker trabeculae, and better trabecular orientation but less connection compared to the CHA group. Immunohistochemistry confirmed the ability of bioreactors to incubate a large-sized substitute coated with viable BMNCs with the potential for proliferation and differentiation. These findings suggested that a bioreactor-activated substitute is comparable to autograft on spine fusion and that new functional bone regeneration could be achieved by a combination of BMNCs, biomaterials, and bioreactors., (© 2022 Wiley Periodicals LLC.)

Background: Patients undergoing sacroiliac (SI) fusion can oftentimes experience significant improvements in pain and quality of life., Objective: To describe a novel application of robotic navigation to assist with minimally invasive SI joint fusion., Methods: Patients undergoing stand-alone SI joint fusion with ExcelsiusGPS robotic navigation from July 2020 through June 2021 were retrospectively enrolled. Baseline demographic and perioperative variables including radiation exposure, postoperative pain scores, and narcotic requirements in the postanesthesia care unit (PACU) were recorded. Length of stay and any postoperative complications were also noted., Results: A total of 10 patients (64.4 ± 8.2 years, body mass index 28.7 ± 4.8 kg/m2) met inclusion criteria. Seven patients (70.0%) were female, and there was a 6:4 split between left-sided and right-sided SI joint fusion. The total operative time was 54 ± 9 minutes, and the estimated blood loss was 21.0 ± 16.7 mL. The intraoperative radiation exposure was 13.7 ± 6.2 mGy, and there were no complications. The average pain score in PACU was 5.2 ± 1.0, and the average opioid administration in PACU was 27.6 ± 10.3 morphine equivalents. Length of stay was 0.4 ± 0.7 days, with 7 of 10 patients discharged on the same day as surgery. There were no readmissions. The average length of follow-up was 4.3 ± 2.5 months. At the last follow-up, patients reported an average of 73.1% ± 30.1% improvement in their preoperative pain., Conclusion: Robot-navigated SI joint fusion is a feasible and reproducible method for addressing refractory SI joint disease. Further investigation on clinical outcomes and long-term fusion rates is needed, as are studies comparing robot-navigated SI joint fusion with more traditional techniques., (Copyright © Congress of Neurological Surgeons 2022. All rights reserved.)

Background: Growing rods (GRs) is a commonly utilized technique for the management of early-onset scoliosis. The significance of the position of the apical vertebrae relative to the rods is not known. The purpose of this study is to analyze the potential effects of the position of the apical vertebrae in relation to the GRs on deformity control through plain radiographs and finite element analysis (FEA) modeling., Methods: We identified 140 patients treated with GR between 2000 and 2018. Patients who had a congenital vertebral anomaly or <2-year follow-up were excluded. Curve magnitude, traction radiograph under general anesthesia (TRUGA) flexibility, apical rotation, the lengths of T1-12, T1-S1, and the instrumented segments were recorded. Patients were divided into 3 groups according to the apical position on the postoperative radiographs: group 1 (both pedicles are between the rods), group 2 (convex rod is between the apical vertebra pedicles), group 3 (both pedicles are lateral to the convex rod). FEA models were created simulating the 3 groups. Both radiographic and FEA data were analyzed to compare the deformity control and growth in each group., Results: Fifty-eight patients were included in the final analyses (mean age 84 mo; range: 38 to 148). Ten patients (17%) were in group 1, 34 (59%) in group 2, and 14 (24%) in group 3. Difference between TRUGA flexibilities was statistically insignificant. Group 3 was the least successful in terms of both height gain and rotational control. FEA showed a decrease in rotation and displacement for every group, however, the residual rotation and displacement was highest in group 3., Conclusions: Bringing the apex in line with the GR increases the capacity of growth preservation as it results in largest height gain and better deformity control. FEA model demonstrated that distraction alone is inadequate for controlling rotation, and with increasing apical translation, residual rotation after distraction also increases., Level of Evidence: Level III., Competing Interests: The authors declare no conflicts of interest., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

Some authors have suggested that thigh extension during the prone lateral transpsoas approach to the lumbar spine provides the theoretical advantage of providing posterior shift of the psoas muscle and plexus and is responsible for its lower rates of nerve injury. We aimed to elucidate the effects of surgical positioning on the femoral nerve within the psoas muscle via a cadaveric study. In the supine position, 10 fresh frozen adult cadavers had a metal wire secured to the pelvic segment of the femoral nerve and then extended proximally along with its L2 contribution. Fluoroscopy was then used to identify the wires on the femoral nerves in a neutral position and with the thigh extended and flexed by 25 and 45°. Additionally, a lateral incision was made in the anterolateral abdominal wall to mimic a lateral transpsoas approach to the lumbar spine, and measurements were made of the amount of movement in the vertical plane of the femoral nerve from neutral to then 25 and 45° of thigh flexion and extension. On fluoroscopy, the femoral nerves moved posteriorly at a mean of 10.1 mm with thigh extension. Femoral nerve movement could not be detected at any degree of this range of flexion of the thigh. Extension of the thigh to about 30° can move the femoral nerve farther away from the dissection plane by approximately one centimeter. This hip extension not only places the femoral nerve in a more advantageous position for lateral lumbar interbody fusion procedures but also helps to promote accentuation of lumbar lordosis., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Study Design: Retrospective longitudinal study., Objective: To identify the preoperative factors associated with postoperative lumbar fusion recovery in back or leg pain, self-reported walking time, and gait speed over a 6-month period., Summary of Background Data: The demand for lumbar fusion surgeries has significantly increased over the years. Yet, some patients report persistent postsurgical pain and poor functional outcomes. Unfortunately, the associated risk factors are not well understood., Methods: The study analyzed 232 subjects with mono- or bisegmental lumbar fusion surgery who underwent standardized assessment preoperatively and at 4, 12, and 24weeks postoperatively. Preoperative variables collected were demographic, clinical, and psychological variables. Back or leg pain was measured by the Numeric Pain Rating Scale. Walking disability was measured by self-reported walking time and performance-based fast gait speed. Risk factors of pain and walking disability over time were identified using ordinal and linear mixed-effects modeling., Results: At 6 months post-surgery, 17% of patients reported having moderate or severe back/leg pain and 24% were unable to walk longer than 30 minutes. Greater preoperative self-reported leg weakness frequency and body-mass-index (BMI) were strongly associated with greater pain and walking disability. Additionally, greater preoperative depression symptoms were associated with greater back/leg pain (adjusted odds ratio = 4.0) and shorter walking time (adjusted odds ratio = 2.7)-but not with slower gait speed (difference = 0.01 m/s). Old age and female gender were strongly associated with gait speed but not with self-reported walking time., Conclusion: A sizable proportion of patients had poor pain and walking outcomes even at 6 months post-surgery. Preoperative leg weakness and BMI were consistent risk factors and patients with greater depression symptoms may have poorer self-reported outcomes. Although requiring validation, our study has identified potentially modifiable risk factors which may give clinicians an opportunity to provide early (preoperative) and targeted intervention strategies to optimize postoperative outcomes., Level of Evidence: NA., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

Scheuermann's disease represents the second most common deformity of the growing spine after the various forms of scoliosis. In cases of early diagnosis and mild kyphotic deformity conservative treatment with a brace and physiotherapy shows very good results; however, in cases of neurologic deficits, curve progression despite conservative treatment and increasing pain symptoms with a Stagnara angle of more than 70-75°, surgical treatment is meaningful. The surgical strategy can include posterior spondylodesis with prior anterior release or posterior instrumentation with posterior column osteotomy depending on the surgeon's experience. The choice of the extent of the operation with the vertebrae to be instrumented and including the straightening method should be oriented to the avoidance of complications, such as proximal or distal junctional kyphosis., (© 2022. The Author(s), under exclusive licence to Springer Medizin Verlag GmbH, ein Teil von Springer Nature.)

Study Design: This was a retrospective cohort study., Objective: The objective of this study was to determine whether race, specifically American white and American black, correlates with the ratio of cancellous to total bone at the iliac crest., Summary of Background Data: Studies have demonstrated higher proximal femur bone density in American blacks than American whites. However, whether differences occur at the iliac crest, a common site for autologous graft material in spinal fusion surgery, is not well studied. Understanding such differences could aid orthopedic surgeon decision-making regarding graft options., Materials and Methods: A retrospective review was performed on 133 sequential patients ages 18-75 who underwent computed tomography scan of the pelvis, at a single academic medical center from January 1, 2014, to January 1, 2016. The cohort included 46 American white (21 females, 25 males) and 87 American black participants (40 females, 37 males), an average age of 51.8 years. Groups were matched regarding age, sex, body mass index, and Charlson Comorbidity Score. Measurements of cortical and cancellous bone thickness in the right and left iliac crests were performed using bone window protocol on computed tomography scans. Statistical significance was determined using a 2-tailed t test., Results: The interobserver interclass correlation coefficient reliability (N=2) for measurements at the right iliac crest is 0.895 (95% confidence interval, 0.852-0.925), and the interclass correlation coefficient for the left iliac crest is 0.912 (95% confidence interval, 0.877-0.938). A statistically significant difference in the mean cancellous bone ratio was found between American black (0.667±0.065) and American white (0.750±0.051) groups (P<0.001)., Conclusions: At the iliac crest, American black patients had a lower mean ratio of cancellous to the total bone as compared with American white patients. This population may benefit from alternative graft options. While iliac crest autograft remains the first option for fusion surgeries, alternative options should be considered to ensure that each patient receives the best-personalized care., Competing Interests: The authors declare no conflict of interest., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

To evaluate the operating range and morphology of the surgical safe zone for oblique lumbar interbody fusion (OLIF). Twenty embalmed full-torso cadaveric specimens were dissected. The oblique corridor and the distance between adjacent lumbar arteries were measured in a static state and with psoas major retraction. The morphology and size of the safe zone for OLIF and the location of the lumbar sympathetic trunk were also recorded. The oblique corridor of the L1-L5 segments was significantly greater in the retracted state than in the static state (p < 0.05). With psoas major retraction, the distances between adjacent lumbar arteries at L1-4 were significantly greater (p < 0.05) than those in the static state. The lumbar sympathetic trunk is just located in the safe zone and travels downward adjacent to the psoas major. The shape of the safe zone for OLIF was approximately an oblique upward parallelogram at L1/2 and L2/3, an isosceles trapezoid at L3/4, and an irregular quadrangle or triangle at L4/5. The safe zone for OLIF at L1/2, L2/3, and L3/4 was significantly larger during retraction than in the static state (p < 0.05). On the lateral side of the lumbar spine there is a natural surgical safe zone for OLIF, which can provide a sufficient operating space. The safe zone has a certain morphological pattern in L1-5 segments and psoas major retraction can significantly enlarge it., (© 2021 American Association of Clinical Anatomists.)

Purpose: Potential asymmetries of the C2 posterior elements pose a problem for the spine surgeon seeking to make the best choice for spinal stabilization while reducing morbidity., Methods: A digital caliper was used to measure the pars interarticularis height and length on left and right sides of 25 adult C2 vertebrae. The pars interarticularis was defined as the bone between the posterior most aspect of the superior articular process and the anterior most aspect of the inferior articular process of C2. Also, the C2 vertebrae from 49 patients were scanned by CT. Parasagittal images were reviewed and using the same definitions as were used for the skeletal specimens, the length and the height of the C2 pars interarticularis from both the left and right sides were measured using CT. The image slices were acquired at 3 mm intervals. The pars interarticularis height was determined on sagittal CT reconstruction, while the pars interarticularis length was calculated on the basis of the axial images., Results: The lengths and the heights of the left and right pars interarticularis were compared using CTs of patients and skeletal specimens. No significant differences were found in the length and height measurements of the CT images on both sides. However, in the skeletal specimens, the left and right pars interarticularis did not differ significantly in length but differed significantly in height (p = 0.003). The mean height of the left pars interarticularis was approximately two times larger than the right in the skeletal specimens. Absolute differences were calculated between the side with the greater length and height and the side with the lesser length and height irrespective of their left-right orientations. For CT measurements, most differences in length and height between the greater pars interarticularis and lesser pars interarticularis occurred between 0 and 1 mm with each successive disparity interval yielding lower numbers. Skeletal measurements revealed a similar length disparity distribution to the CT measurements. However, height measurements in the skeletal specimens varied widely. Eight pars interarticularis specimens demonstrated a height difference between 0 and 1 mm. No dry bone pars interarticularis specimens demonstrated a height difference between 1 and 2 mm. The pars interarticularis of nine specimens demonstrated a height difference between 2 and 3 mm. Two demonstrated a height difference between 3 and 4 mm. Four demonstrated a height difference between 4 and 5 mm and two demonstrated a height difference greater than 5 mm. The greater pars interarticularis lengths and heights were combined and compared to their lesser counterparts on CT and skeletal measurements. In all measurements of this type, significant differences were found in the pars interarticularis length and height, whether measured through CT or via digital calipers., Conclusion: Asymmetry between the left and right C2 pars interarticularis as shown in the present study can alter surgical planning. Therefore, knowledge of this anatomical finding might be useful to spine surgeons., (© 2022. The Author(s), under exclusive licence to Springer-Verlag France SAS, part of Springer Nature.)

The article presents summaries of articles on neuroscience, published as of March 2018. Topics include impact of postoperative bracing on pain and quality of life after posterior spinal instrumented fusion (PSIF), implantation of an empty polyetheretherketone cage in anterior cervical discectomy and fusion, and comparison between tubular discectomy and conventional microdiscectomy for the treatment of lumbar disc herniation.

Background: Limiting complications, especially unplanned return to the operating room (UPROR), is a major focus in the surgical management of early-onset scoliosis (EOS). Although UPROR remains common in this population, its effect on long-term health-related quality of life (HRQoL) remains unclear. The purpose of this study was to investigate the association between UPROR and end-of-treatment HRQoL in EOS patients treated with growth-friendly instrumentation., Methods: Patients with EOS who underwent growth-friendly instrumentation at age less than 10 years from 1993 to 2018, and completed treatment, were identified in a multicenter EOS registry. UPROR events were recorded, and end-of-treatment (defined as skeletal maturity and/or definitive spinal fusion) HRQoL was assessed via the 24-item Early-Onset Scoliosis Questionnaire (EOSQ-24)., Results: A total of 825 patients were identified, and 325 patients (age at surgery: 6.4 y, follow-up: 8.1 y) had end-of-treatment HRQoL data necessary for our investigation. Overall, 129/325 (39.7%) patients experienced 264 UPROR events; the majority (54.2%) were implant-related. Aside from age and etiology, no other variables were determined to be confounders or effect modifiers. Congenital patients with UPROR had worse pain/discomfort by 10.4 points (P=0.057) and worse pulmonary function by 7.8 points (P=0.102) compared with non-UPROR patients adjusting for age. Neuromuscular patients with UPROR had worse pulmonary function by 10.1 points compared with non-UPROR patients adjusting for age (P=0.037). Idiopathic and syndromic patients with UPROR reported consistently worse domain scores than their non-UPROR counterparts, but smaller (<5-point) differences were seen., Conclusions: UPROR during growth-friendly surgical treatment for EOS is associated with worse HRQoL in all patients, but particularly in those with neuromuscular or congenital etiologies. Ongoing efforts to avoid UPROR are critical., Level of Evidence: Level II. This is a multicenter retrospective cohort study investigating the effect of UPROR on HRQoL (prognostic study)., Competing Interests: The authors declare no conflicts of interest., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Introduction: Various surgical techniques have been introduced for atlantoaxial (C1-C2) fusion, the most common being Magerl's (transarticular) or the Harms/Goel screw fixation. Common indications include degenerative osteoarthritis (OA), trauma or rheumatoid arthritis (RA). Only few, small studies have evaluated patient-reported outcomes after C1-C2 fusion. We investigated 2-year outcomes in a large series of consecutive patients undergoing isolated C1-C2 fusion., Methods: We analysed prospectively collected data (2005-2016) from our Spine outcomes database, collected within the framework of EUROSPINE's Spine Tango Registry. It included 126 patients (34 (27%) men, 92 (73%) women; mean (SD) age 67 ± 19 y) who had undergone first-time isolated C1-C2 fusion (61% Magerl, 39% Harms(-Goel)) at least 2 years ago for OA (83 (66%)), RA (20 (16%)), fracture (15 (12%)) or other (8 (6%)). Patients completed the multidimensional Core Outcome Measures Index (COMI; 0-10) and various single item outcomes., Results: Questionnaires were returned by 118/126 (94%) patients, 2 years post-operative. Mean COMI scores showed a significant reduction from baseline: 6.9 ± 2.4 to 2.7 ± 2.5 (p < 0.0001). Overall, 75% patients achieved the MCIC of ≥ 2.2 points reduction in COMI and 88% reported a good global outcome. 91% patients were satisfied/very satisfied with their care. Self-reported complications were declared by 16% patients and further surgery at the same segment, by 2.5%., Conclusion: In this large series with almost complete follow-up, C1-C2 fusion showed extremely good results. Despite the complexity of the intervention, outcomes surpassed those typically reported for simple procedures such as ACDF and lumbar discectomy, suggesting reservations about the procedure should perhaps be reviewed., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

The sacroiliac joint (SIJ) is a known pain generator that, in severe cases, may require surgical fixation to reduce intra-articular displacements and allow for arthrodesis. The objective of this computational study was to analyze how the number of implants affected SIJ stabilization with patient-specific characteristics such as the pelvic geometry and bone quality. Detailed finite element models were developed to account for three pelvises of differing anatomy. Each model was tested with a normal and low bone density (LD) under two types of loading: compression only and compression with flexion and extension moments. These models were instrumented with one to three cylindrical, threaded and fenestrated implants through a posterior oblique trajectory, requiring less muscle dissection than the more common lateral trajectory used with triangular implants. Compared with the noninstrumented pelvis, the change in range of motion (ROM) and stress distribution were used to characterize joint stabilization. Noninstrumented mobility ranged from 0.86 to 2.55 mm and from 1.37° to 6.11°. Across patient-specific characteristics, the ROM reduction with one implant varied from 3% to 21% for vertical and 15% to 47% for angular displacements. With two implants, the ROM reduction ranged from 12% to 41% for vertical and from 28% to 61% for angular displacements. Three implants, however, did not further improve the joint stability (14% to 42% for vertical and 32% to 63% for angular displacements). With respect to patient characteristics, an LD led to a decreased stabilization and a higher volume of stressed bone (>75% of yield stress). A better understanding of how patient characteristics affect the implant performance could help improve surgical planning of sacroiliac arthrodesis., (© 2021 Orthopaedic Research Society. Published by Wiley Periodicals LLC.)

Study Design: A randomized, double-blind, placebo-controlled clinical trial., Objective: To evaluate the efficacy and safety of tranexamic acid (TXA) administered during the surgical correction of thoracolumbar fracture-dislocation., Summary of Background Data: Thoracolumbar fracture-dislocation surgery is generally associated with substantial blood loss and a high risk of deep vein thrombosis. TXA has been shown to improve hemostasis in surgical procedures., Methods: We investigated 80 patients with thoracolumbar fracture-dislocation who underwent transforaminal thoracic interbody fusion between March 2014 and December 2016. The patients were randomized into the TXA (n = 39) and Placebo (n = 41) groups, according to whether they did or did not receive pre- and intraoperative TXA treatment. The two groups were compared for demographic characteristics as well as pre- and postoperative levels of prethrombosis-state molecular markers and visible and hidden blood loss volumes. Additionally, the prevalence of TXA-related complications was determined., Results: The two groups did not differ significantly in demographic characteristics. The visible blood loss (intra- and postoperative bleeding during the first 24 h), hidden blood loss, and true total blood loss during surgery in the TXA group were significantly lower than those in the Placebo group (835 ± 180.3 mL, 351 ± 82.3 mL, 1385 ± 102.3 mL vs. 1155 ± 175.3 mL, 564 ± 170.5 mL, 1683 ± 121.0 mL, respectively; P < 0.01). Furthermore, the levels of the prethrombosis-state molecular markers GMP-140, fibrinogen, fibrin degradation products, and D-dimer were higher in the TXA group than in the Placebo group, although the differences were not significant (P > 0.05). No significant intergroup differences were noted in the prevalence of deep venous thrombosis and pulmonary embolus during the study period., Conclusion: TXA significantly reduced visible and hidden blood loss without affecting the prethrombosis-state molecular markers in transforaminal thoracic interbody fusion or causing any notable adverse effects., Level of Evidence: 3.

Study Design: Retrospective cohort study., Objective: The purpose of this study is to investigate the incidence of surgical site infection in neuromuscular scoliosis (NMS) patients at a tertiary children's hospital before and after the implementation of strategies mentioned in the 2013 Best Practice Guideline., Summary of Background Data: Patients with NMS are at high risk for surgical site infection following spine surgery. In 2013, a Best Practice Guideline for surgical site infection prevention in high-risk pediatric spine surgery patients reported strategies to decrease incidence. To date, no studies have looked at the efficacy of these strategies., Methods: A retrospective review of surgical site infection in NMS patients was performed. NMS patients undergoing primary posterior spinal fusion from January 2008 to December 2012 (Group 1) and January 2014 to December 2018 (Group 2) were included, with 2013 excluded as a transition year. The primary outcome was incidence of surgical site infection within 1 year of surgery, as defined by the Centers for Disease Control and National Healthcare Safety Network. All patients had at least 1 year of documented follow-up., Results: One hundred ninety eight patients were included, 62 in Group 1 and 136 in Group 2. Age, BMI, sex, fusion to pelvis, preoperative Cobb angle, incontinence, drain use, blood loss, surgical time, and other perioperative values were similar (P > 0.05). Deep surgical site infection occurred in 10 (16.1%) patients in Group 1 and six (4.4%) patients in Group 2 (P = 0.005). Thirteen (59.1%) identified organisms were gram-negative, with 11 (84.6%) isolated from Group 1 (P = 0.047). Polymicrobial infections accounted for six (37.5%) infections overall., Conclusion: The incidence of surgical site infection in NMS patients decreased significantly (16.1% vs. 4.4%) after the implementation of the strategies mentioned in the 2013 Best Practice Guideline. Further studies are required to continue to decrease the incidence in this high-risk population.Level of Evidence: 3., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Study Design: Cross-sectional study., Objective: To analyze the feasibility of anterior spinal access to the vascular corridor at the L5-S1 junction, by evaluating three crucial anatomical landmarks. This provides a framework for risk-stratification for the clinician during preoperative evaluation., Summary of Background Data: The anterior lumbar interbody fusion (ALIF) offers many advantages for fusion at the L5-S1 junction. However, the variant iliac vasculature may preclude safe anterior access., Methods: Five hundred magnetic resonance imaging (MRI) images of the L5-S1 level were identified, with 379 meeting inclusion criteria. We graded the anterior access into three grades, namely, easy, advanced, or difficult by looking at three important anatomical landmarks-the vascular corridor (narrow if ≤25 mm, medium if 25-35 mm [inclusive], and wide if >35 mm), the left common iliac vein (LCIV) location (grades A-D based on the relative position of the LCIV to the L5-S1 disc space), and the presence or absence of a fat plane., Results: Our results showed that 43.27% of the patients had wide corridor for the anterior access, 19.26% of patients had no fat plane, and 7.65% had a LCIV that extended past the midline of the disc (Grade C, D: >50%). By combining these three factors, 37.20% would have easy anterior access, while a minority (1.85%) would have a difficult anterior access., Conclusion: The ALIF at L5-S1 offers significant benefits to the patient. The surgeon should be aware of the dangers in an anterior access by looking at three crucial factors to determine whether the access is easy, advanced, or difficult. Patients with a difficult access should be attempted by experts, vascular access surgeons, or consider an alternative approach to L5-S1.Level of Evidence: 3., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)